As is well known, many utility installations, for example sewer pipes, waste water pipes, electric cable conduits, mains' water supply control valves, transformers, and the like, are positioned below ground level. Access to these utility installations is generally achieved by climbing through an entrance hole at ground level and down a vertically extending access conduit, usually a cylindrical pipe having a diameter large enough to permit a person to gain access to the utility installation.
The access conduit entrance is invariably provided with a utility access cover which is usually fabricated from a rigid robust material such as cast iron or reinforced concrete and, as a result, is heavy and difficult to maneuver. The utility access covers most generally used are fabricated from cast iron and have at least two holes near to the outer circumferential edge of the cover for use in removing the cover from the entrance hole. In position, the cover is seated in a cover support ring situated such that the cover and the ring are substantially in the plane of the surrounding surface, such as that of the road or sidewalk surface. The technique usually employed for lifting and maneuvering these covers is to use a crow bar, trap hook, or similar metallic rod-like tool by inserting the tool into one of the holes in the cover and pulling the tool upwards and outwards towards the operator, relying on friction between the cover and the tool to effect lifting of the cover. Alternatively, the cover may be removed by forcing the cover out of its support ring by jamming the tool between the outer peripheral edge of the cover and the support ring. In both instances, very little control over the movement of the cover can be maintained and, furthermore, there is always the chance that the cover may drop off the tool and injure the operator, for example by falling on his legs or feet.
In light of the above, it can be appreciated that there exists a significant need for a tool which can be conveniently used to lift and maneuver utility access covers, especially heavy cast iron manhole covers, while maintaining complete control over the movement of the cover and without risk of the cover becoming disengaged from the tool and possibly injuring the person lifting the cover.
In order to prevent access to utility installations of the type mentioned above by unauthorized personnel, for example children, it is becoming common practice to provide utility access covers with locking devices. One locking device which is finding increasing use for this purpose is that described in U.S. Pat. No. 3,751,949 to Alfred B. Castle, the inventor of the invention of the present application. It would accordingly be desirable to provide a tool which is adapted for lifting and maneuvering utility access covers which are provided with a locking device, such as that described in the above-mentioned United States patent. Other locking systems which can be readily adapted for use with utility access covers have been invented by Alfred B. Castle, and these are described in U.S. Pat. Nos. 2,608,085; 3,201,161; and 3,751,949. Insofar as the disclosures of these patents are relevant to the present application in that they disclose locking systems which may be used with utility access covers, the disclosures of the four United States patents mentioned above are specifically incorporated herein by reference.